[WEB-4428] fix: duplicate labels with case insensitive (#7388)

Co-authored-by: sriramveeraghanta <veeraghanta.sriram@gmail.com>

apps/api/plane/tests/unit/serializers/test_label.py

@@ -0,0 +1,43 @@
+import pytest
+from plane.app.serializers import LabelSerializer
+from plane.db.models import Project, Label
+
+
+@pytest.mark.unit
+class TestLabelSerializer:
+    """Test the LabelSerializer"""
+
+    @pytest.mark.django_db
+    def test_label_serializer_create_valid_data(self, db, workspace):
+        """Test creating a label with valid data"""
+        project = Project.objects.create(
+            name="Test Project", identifier="TEST", workspace=workspace
+        )
+
+        serializer = LabelSerializer(
+            data={"name": "Test Label"},
+            context={"project_id": project.id},
+        )
+        assert serializer.is_valid()
+        assert serializer.errors == {}
+        serializer.save(project_id=project.id)
+
+        label = Label.objects.all().first()
+        assert label.name == "Test Label"
+        assert label.project == project
+        assert label
+
+    @pytest.mark.django_db
+    def test_label_serializer_create_duplicate_name(self, db, workspace):
+        """Test creating a label with a duplicate name"""
+        project = Project.objects.create(
+            name="Test Project", identifier="TEST", workspace=workspace
+        )
+
+        Label.objects.create(name="Test Label", project=project)
+
+        serializer = LabelSerializer(
+            data={"name": "Test Label"}, context={"project_id": project.id}
+        )
+        assert not serializer.is_valid()
+        assert serializer.errors == {"name": ["LABEL_NAME_ALREADY_EXISTS"]}